The present invention relates to a process for forming shaped ceramic articles such as for example abrasive particles with a high degree of flexibility and productivity. It relates particularly to shaped articles made from a dispersion of an alpha alumina precursor.
Shaped alumina articles in the form of filamentary abrasive particles made by a seeded sol-gel process have been shown, in U.S. Pat. No. 5,009,676, to have certain significant advantages over grains having random shapes made by grading crushed larger pieces of abrasive. Methods of forming such shaped grains are disclosed in U.S. Pat. Nos. 5,090,968 and 5,201,916. Other kinds of shaped article made from sol-gel alumina such as discs and fibers and thin sheets have also been described. Most of these processes are however not well adapted to the manufacture of very small shaped abrasive particles.
A new and very flexible process for the production of shaped alumina articles has now been devised that allows very rapid and efficient production from a dispersion of a precursor material. The process of the invention is particularly well adapted to the production of very fine particles by an easily automated technique.
While this invention is very flexible as to the nature of the shapes produced it is particularly adapted to the production of shaped abrasive particles.